Crank No Start after Taurus Short Block Swap

[Tater55]

Pretty long post here so I’ll try to compress.

Last year, my 2000 3.0L FFV ranger was idling really bad and running really rich, even though both banks read “lean” when scanned for codes. After throwing plenty of parts and sensors at it and not changing anything, it eventually got worse to the point that it lost compression.

I took the heads off and decided to get them machined. At that point, I decided to take the rest of the engine out and do a full rebuild. Long story short, being my first rebuild, I didn’t blow the main cap bolt holes out after getting the block back from the machine shop, screwed a bolt in the hole to plasti gauge the crank, and stripped the bolt hole.

So at this point, I decided to ditch the full rebuild and grabbed me a 3.0L from a 2003 Taurus.

I stripped the Taurus engine down to pretty much the “short block”. Block, pistons, crank, cam, lifters, cam and crank sensors.

I transferred over from my truck the oil pan, intake, reworked heads, new timing chain for the ranger, new oil and water pump, and used the car pushrods and rocker arms. Pushrods were the same length as the truck rods. I’ve read of people using the same car cam in the truck and not having issues so I left it.

I got everything buttoned up this weekend and ready to start but it’s not starting. It’ll crank but wont start and sends a big cloud of what I’m assuming is unburnt fuel out the exhaust. Yesterday after work, I tried to start it again and got it to start for a couple of seconds by pressing the gas pedal all the way to the floor while cranking, which I’ve read shuts the injectors off as long as you hold the pedal. Once it starts, it backfires quite a bit and stays on for 4-5 seconds as long as I give it gas, then completely shuts off.

I have fuel at the fuel rail, even though I haven’t put a gauge to it. Certain I have spark. Have not checked compression, which I would guess I have some compression if I got it to start for a couple seconds.

I also ordered a FORScan adapter for my laptop along with the “license” to be able to use their software. It should be here next week. For now, I have my in-laws generic scanner wich only allows me to see codes and short/long term fuel trims as well as spark timing.

 

[franklin2]

With experience you can listen to it crank and see if you have even compression. Or you can do a compression check. If something is wrong somewhere, you will not have even compression on all cylinders. I have never done this swap, but I can see timing being off, valves not in adjustment, etc. Any of these will cause a compression problem on several or all cylinders.

 

[Tater55]

With experience you can listen to it crank and see if you have even compression. Or you can do a compression check. If something is wrong somewhere, you will not have even compression on all cylinders. I have never done this swap, but I can see timing being off, valves not in adjustment, etc. Any of these will cause a compression problem on several or all cylinders.

I can hear compression, especially with only the exhaust manifolds bolted on. I haven’t put a gauge on it to check if I have sufficient compression.

 

[Tater55]

Used the wrong spark plug wiring diagram in my Haynes manual. Switched them around and it fired up.

Now its back to doing the same thing it was before the other engine went out. Idling really bad to the point that it turns off. Still getting the same P0176 Code which is the flex fuel sensor circuit.

Is there anyway I can tune that sensor out? I’m tired of dealing with it.

 

[RonD]

It reads like you have a Computer(PCM) issue and had that from the start of the rough running, pre-engine swap

2000 Flex Fuel PCM may still use the Fuel Sensor, by the fuel filter, to detect fuel type and percentage, gasoline/ethanol
Ethanol mix is VERY rich 9 to 1 vs 14 to 1 for gasoline
So PCM could be stuck in Ethanol "mode" or ??

These Fuel sensors did fail but if its just telling PCM its seeing E80(80% ethanol) when its actually gasoline then it has failed but not as far as PCM is concerned, because its getting a "good" reading, just not a correct reading
PCM has no other "sensor" to detect that type of failure

Look under the truck to see if you have this sensor, 3 wire connector, and has in and out fuel lines

 

[Tater55]

It reads like you have a Computer(PCM) issue and had that from the start of the rough running, pre-engine swap

2000 Flex Fuel PCM may still use the Fuel Sensor, by the fuel filter, to detect fuel type and percentage, gasoline/ethanol
Ethanol mix is VERY rich 9 to 1 vs 14 to 1 for gasoline
So PCM could be stuck in Ethanol "mode" or ??

These Fuel sensors did fail but if its just telling PCM its seeing E80(80% ethanol) when its actually gasoline then it has failed but not as far as PCM is concerned, because its getting a "good" reading, just not a correct reading
PCM has no other "sensor" to detect that type of failure

Look under the truck to see if you have this sensor, 3 wire connector, and has in and out fuel lines

Forgot to mention, I do have the flex fuel sensor. Prior to my first engine going out, I bought the device they sell online that’ll “bypass” the flex fuel sensor and trick the PCM into thinking it’s working correctly. I installed the device and still ran the same, no change.

I was leaning into a faulty PCM prior to taking the engine out, but had no real way of telling sense the engine wouldn’t start, therefore I couldn’t troubleshoot further.

 

[Tater55]

Also, upon browsing ranger forums, I came to the realization that I installed my head gaskets on backwards. The open coolant ports on the gaskets were facing forward when I installed them, they’re supposed to be in the back.

Bummer since everything is already buttoned up and running. I’ve read people run them that way and don’t overheat or leak, should I just bite the bullet and tear down/reassemble? Or should I see how it runs first?

 

[RonD]

It does cause hot spots in the engine, but I doubt it would lead to catastrophic failure

If you start to hear "thumping" noise in heater system or after shut down you may want to redo the head gaskets
The "thumping" is caused by a hot spot turning a very small amount coolant to steam, the instant expansion cause the "thump"

The Fuel Type Sensor Emulator does work, and takes failing fuel type sensor off the table
If you have an OBD2 reader see if you can find a Fuel Type listing in the computer
Seen here: https://en.wikipedia.org/wiki/OBD-II_PIDs#Fuel_Type_Coding

Should see Bifuel running gasoline, if computer is OK

 

[Tater55]

It does cause hot spots in the engine, but I doubt it would lead to catastrophic failure

If you start to hear "thumping" noise in heater system or after shut down you may want to redo the head gaskets
The "thumping" is caused by a hot spot turning a very small amount coolant to steam, the instant expansion cause the "thump"

The Fuel Type Sensor Emulator does work, and takes failing fuel type sensor off the table
If you have an OBD2 reader see if you can find a Fuel Type listing in the computer
Seen here: https://en.wikipedia.org/wiki/OBD-II_PIDs#Fuel_Type_Coding

Should see Bifuel running gasoline, if computer is OK

Awesome, I will check fuel type first thing in the morning with this scanner that I have. If not, my FORScan scanner should be here mid week this week.

I will update tomorrow, thanks for the useful information.

 

[Tater55]

It does cause hot spots in the engine, but I doubt it would lead to catastrophic failure

If you start to hear "thumping" noise in heater system or after shut down you may want to redo the head gaskets
The "thumping" is caused by a hot spot turning a very small amount coolant to steam, the instant expansion cause the "thump"

The Fuel Type Sensor Emulator does work, and takes failing fuel type sensor off the table
If you have an OBD2 reader see if you can find a Fuel Type listing in the computer
Seen here: https://en.wikipedia.org/wiki/OBD-II_PIDs#Fuel_Type_Coding

Should see Bifuel running gasoline, if computer is OK

I checked my scanner again this morning and couldn’t find the Fuel Type display. I’m not sure if it just simply doesn’t display it, or I just haven’t been able to locate it.

However, I did find a “pinpoint test” for the flex fuel sensor circuit online, so I started that this morning. I tapped a small gauge wire into the negative battery terminal and ran the other end to the underside of the truck where I could reach it while messing with the FF sensor connector.

As mentioned before, it’s a three prong connector. From left to right the wires at the connector are- (light grn/dark grn) - (blue/red) - (black). With the key on, I hooked my negative lead on my fluke t5 meter to the wire tapped into the negative terminal and used my positive lead to check for voltage at the connector pins. These were the readings:
Light grn/dark grn = 3V
Blue/Red = 12V
Black = 0V

I was unable to find the circuit in my Haynes manual wiring diagram, so I concluded that
Light grn/dark grn = Signal
Blue/Red = Power
Black = Ground
Not sure if my conclusion is correct.

The second step in the pinpoint test was to test for resistance between the battery negative side and the connector ground terminal. The test says if your resistance reads less than 10,000 ohms, then it’s fine, move to next step. If your resistance reads more than 10,000 ohms, you have an open circuit.

My resistance reading between the battery negative post and the connector “ground” wire was 37Kohms = 37,000ohms.

With that said, am I right to think that there is a lack of ground in the FF circuit?

 

[RonD]

Fuel type sensor uses Hz as the signal not voltage, 60-70Hz is Gasoline, 60-63Hz is straight gasoline, 65-68Hz is 10% ethanol, 70% is 15%
You should be able to see the Hz the computer is seeing on an OBD2 reader

Yes, I would expect ground wire to be 0 ohms to any vehicle ground, depending on the scale you use
And as far as I known this sensor is a 12volt model, unlike most other sensors
So needs 12v and Ground to operate correctly

If you Meter has a Hz setting then you can use that to check signal wire

 

[Tater55]

Fuel type sensor uses Hz as the signal not voltage, 60-70Hz is Gasoline, 60-63Hz is straight gasoline, 65-68Hz is 10% ethanol, 70% is 15%
You should be able to see the Hz the computer is seeing on an OBD2 reader

Yes, I would expect ground wire to be 0 ohms to any vehicle ground, depending on the scale you use
And as far as I known this sensor is a 12volt model, unlike most other sensors
So needs 12v and Ground to operate correctly

If you Meter has a Hz setting then you can use that to check signal wire

This is what the freeze frame looks like for the P0176 code.

I tried looking for the Hertz value the computer was reading, but was unable to find it with this scanner.

 

[Tater55]

I tapped into the ground wire right behind the connector and spliced a wire into the ground wire. I spliced the other end of that wire to a known ground source in the engine bay. I then plugged the emulator back into the connector and started the truck, nothing changed. I unplugged the emulator and plugged the connector into the FF sensor and same thing, nothing changed.

 

[RonD]

ECT shows too cold to test anything at 127degF, needs to be above 150degF to be fully in Closed Loop(O2 sensors being used)

Load is not related to fuel

P0176 Fuel Composition Sensor Circuit Malfunction
Is the emulator plugged back in?
If so clear the code, as it could have been set when you were testing with key on

 

[Tater55]

ECT shows too cold to test anything at 127degF, needs to be above 150degF to be fully in Closed Loop(O2 sensors being used)

Load is not related to fuel

P0176 Fuel Composition Sensor Circuit Malfunction
Is the emulator plugged back in?
If so clear the code, as it could have been set when you were testing with key on

Ok, cleared the codes with engine off. Plugged emulator back in with makeshift ground wire running into the engine bay.

Got ECT up to 192, is idling fine, but the codes came back.